Iatrogenic Hypoparathyroidism with Case

00:01 Let's go on to a case.

00:03 A 48 year old female complains of a tingling sensation in her fingertips as well as the skin around of her mouth which woke her from sleep.

00:11 She is on the post-operative floor and she's just undergone a complete thyroidectomy for papillary thyroid cancer.

00:21 Her temperature's 37 degrees celsius, her respirations are 15 breaths per minute, her pulse rate is 67 beats per minute and a blood pressure 122/88 While recording the blood pressure, spasm of the muscles of the hand and forearm is seen as shown in the image.

00:42 A 12-lead EKG also reveals a prolonged QT-interval.

00:47 What is the next best step in the management of this patient? In reviewing this presentation, this patient has just had thyroid surgery and is now manifesting the classic symptoms of hypocalcemia.

01:00 On physical exam, she has Trosseau's sign and prolonged QTc interval.

01:07 In hypocalcemia, one of the classic manifestations on EKG is the prolongation in the distance between the Q wave and the T wave on the EKG This is known as the QT interval and in this clinical setting, is significant because it implies that the patient's calcium level is very low This patient has acute hypoparathyroidism and the calcium and parathyroid hormone level should be checked.

01:34 This will confirm the diagnosis and the patient should have immediate supplementation of calcium.

01:40 Calcium should be replaced in this patient as they're exhibiting signs of hypercalcemia following total thyroidectomy All four parathyroid glands are rarely removed during thyroid surgery.

01:52 Unfortunately, when it does occur, results in hypoparathyroidism.

01:58 Lifelong calcium supplementation is usually required for these patients.

02:03 It can occur in the Hungry bone syndrome.

02:06 This occurs when patients have surgery for hyperparathyroidism and undergo a parathyroidectomy and as a consequence of the bones being deprived of calcium for a prolonged period of time because the patient has had hyperparathyroidism, the post operative phase can manifest with severe reductions in serum calcium as the bones reabsorb calcium from the circulation.

02:32 Let’s talk about a condition called Hungry Bone syndrome.

02:36 This condition is characterized by hypocalcemia and the rapid influx of calcium into the bone after parathyroid surgery.

02:45 Patients who undergo parathyroid surgery usually experience transient hypocalcemia, but in hungry bone syndrome, the underlying parathyroid-mediated bone turnover disease results in an imbalance of osteoblast and osteoclast activity.

03:03 This then leads to a more pronounced refractory form of hypocalcemia.

03:09 This condition is usually seen in patients with underlying renal dysfunction, and it is treated with calcium supplementation.

03:18 The most common cause of iatrogenic hypoparathyroidism is inadvertent injury during anterior neck surgery like a thyroidectomy or a parathyroidectomy, both of which present within a few hours of surgery.

03:31 Depending upon the extent of injury or resection, surgical hypoparathyroidism may last days to weeks.

03:39 Permanent hypoparathyroidism when it is complete, there is an undetectable serum PTH level and a higher prevalence of a hyperphosphatemia.

03:48 In a partial parathyroidectomy where there is still some gland remaining, inappropriately normal PTH levels may be found with concurrent hypocalcemia.